Continuation of in vitro and in vivo studies of synovium in acute trauma will utilize closed animal models designed to mimic human injuries. A one year followup of several different types of intra-articular trauma is planned. Arthrotomy, cartilage scarification, ligament resection, closed ligament avulsions, direct contusions, and immunologic arthritis are the models selected. Correlation of in vivo degradative activity, as measured by synovial lysosomal enzyme levels, histologic ultrastructural and histochemical appearance of synovium and cartilage substrate, and with a system utilizing labelled articular chondrocyte monolayer cultures as a substrate will be sought. Further study of the feasibility of utilizing labelled metabolizing articular chondrocyte cultures in in vitro studies of an artificial joint is planned. The docummentation of specific biochemical sequences from acute trauma to established irreversible traumatic arthritis, or to successful healing, is planned.